### nth

<aux-code
    src="andy-aui-css/ui/dev/_nth.scss"
></aux-code> 

#### nth-child

#### nth-index

example
```scss
@include nth-index(1);
@include nth-index(1n);
```

#### nth-not-index

#### nth-not-first

#### nth-not-last 

#### nth-only-index

#### nth-grid
选择第几行第几列

#### nth-index-last

#### nth-range

#### nth-of-type

#### nth-of-type-index

example
```scss
@include nth-of-type-index(1);
@include nth-of-type-index(1n);
```

#### nth-of-type-not-index

#### nth-of-type-not-first

#### nth-of-type-not-last 

#### nth-of-type-only-index

#### nth-of-type-grid

#### nth-of-type-index-last

#### nth-of-type-range